SEEMINGLY BROKEN beyond healing, Lebanon does not often draw the attention of outsiders anymore. But the lifting of the siege of two Palestinian refugee camps in southern Beirut is different. First there was the little shock of recognition, mixed perhaps with a trace of guilt, to find that one of the camps is the same Shatila where Christian Lebanese militia units killed hundreds in the Israeli invasion of 1982. There was the second shock of being reminded that Shatila and its mate in misery, Burj al Barajinah, had been blockaded for no less than three years. The tens of thousands of people living there were regularly bombarded and denied food and medicine, and hundreds of them, conceivably thousands, died.

Three years ago the Palestine Liberation Organization, attempting to rebuild the position in Lebanon it had lost in its war with Israel in 1982, started slipping soldiers and arms back into the slums of Shatila and Burj al Barajinah. Israel was no longer there to cut the PLO down, but Syria, the would-be imperial power in Lebanon, was. To do the dirty work, Damascus recruited the Lebanese Shiite Moslem militia called Amal, whose people had suffered greatly from PLO muscling and from PLO-provoked Israeli attacks on Lebanon. Amal vs. the PLO: the ''camp war.''

By late last year, mutual exhaustion had produced feelers for a truce. Still, it took recent events in the West Bank and Gaza to give Amal the pretext -- solidarity with Palestinians under Israeli rule -- that it needed to back off. Syrian soldiers have taken over the checkpoints under orders, it seems, to keep a tight grip but to let most residents come and go.

The PLO is bent on building up its armed might, Amal will be no less protective of its community, and the Syrian goal remains control. These considerations mean it is foolish to expect permanent relief for Shatila and Burj al Barajinah. The ultimate answer for them and the rest of Lebanon is a restoration of government authority; this remains an ambitious project that hinges in good part on another ambitious project, an Israeli-Palestinian settlement.

Perhaps it is enough to observe that the camp people have gone through an awesome ordeal, one entailing in objective terms far heavier losses and much greater international indifference than the current plight of Palestinians on the West Bank. This ordeal is not over, but it may be a little easier to bear today than it was yesterday, and in Lebanon that is no small triumph.